Ds400 Dual Controller Fabric Attachment - IBM TotalStorage DS300 Best Practices Manual

Figure 8-4 DS400 dual controller direct attachment
Important: Assign logical drives within an individual array only to a single host
system in this configuration. Otherwise the access of a second host system
with to a logical drive may be interrupted, if the first host system forces a
controller failover for the array.

8.3.3 DS400 dual controller fabric attachment

In case that more than two host systems should be attached with multiple paths
to a DS400 dual controller model, SAN switches are necessary. To prevent single
points of failure, two SAN switches or SAN directors should be used.
Chapter 8. TotalStorage DS400 example configurations
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